Question Discussion & Solution

Key Points

Thus, the correct match is A (III), B (II), C (IV), D (I)

The correct answer is Accumulator.

Key Points

• An accumulator is a type of register present in a CPU (Central Processing Unit).
• It works as a temporary storage location that keeps an intermediate value in logical and mathematical calculations.
• Intermediate results of execution are progressively stored in the accumulator, replacing the previous value.

Additional Information

• An IR (Instruction Register) saves machine instruction that is currently under execution. It is a register that sits at the top of the memory hierarchy. A variety of registers fulfills different operations in a central processing unit (CPU) – the function of the IR is to keep that currently stacked instruction for use.
• A PC (program counter) is a CPU register that has the address stored for the next instruction to be processed from memory. It is a digital counter required for quicker execution of tasks as well as to keep track of the current execution point. 
• The MAR (Memory Address Register) is the register in the control unit that holds the address of a register to receive or store from or to the storage. The Memory Address Register is half of an interaction between a microprogram and storage.

1) × and ÷

Given statement: 46 ÷ 2 -­ 7 × 3 + 5 = 39

On interchanging the above signs,

46 × 2 ­- 7 ÷ 3 + 5

= 46 × 2 ­- 2.33 + 5

= 92 ­- 2.33 + 5

= 97 -­ 2.33

= 94.67 ≠ 39

2) ­- and ×

Given statement: 46 ÷ 2 -­ 7 × 3 + 5 = 39

On interchanging the above signs,

46 ÷ 2 × 7 -­ 3 + 5

= 23 × 7 -­ 3 + 5

= 161 ­- 3 + 5

= 166 ­- 3

= 163 ≠ 39

3) + and ×

Given statement: 46 ÷ 2 -­ 7 × 3 + 5 = 39

On interchanging the above signs,

46 ÷ 2 7 + 3 × 5

= 23 ­- 7 + 3 × 5

= 23 ­- 7 + 15

= 38 7

= 31 ≠ 39

4) + and ­-

Given statement: 46 ÷ 2 -­ 7 × 3 + 5 = 39

On interchanging the above signs,

46 ÷ 2 + 7 × 3 ­- 5

= 23 + 7 × 3 ­- 5

= 23 + 21 ­- 5

= 44 -­ 5

= 39

Let’s check each option,

Thus, the sequence is wxwzwy wxwzwy wxwzwy.

Concept:

System modelling is the process of developing abstract models of a system and each model presenting a different view or perspective of that system. 

Explanation:

Concept that has to be considered while modelling a new system are:

Abstraction: at highest level of abstraction, a solution is stated in broad terms while at the lowest level of abstraction a more detailed solution is provided.

Modularity: it is the single attribute of the software that allows a program to be individually manageable.

Information hiding in this algorithms and data contained within a module are inaccessible to to other modules.

Some other factors that are considered are: architecture, pattern, functional independence, refinement, refinement.